Loading and unloading device



v March 21, 1944. T R Ro mso 2,344,923

' Lemme AND UNLOADING DEVICE Filed Sept. 2, 1939 5 Sheets-Sheet l INVEN TOR.

I Home: liRab/nsm A TTORNEK March 21, 1944. R ROBlNSON 2,344,923

LOADING AND UNLOADING DEVICE Filed Sept. 2, 1939 5 Sheets-Sheet 2 53 12 INVEN TOR. 7720mm R/fobmson 65 ATTORNEY.

March 21, 1944; R ROBINSON 2,344,923

LOADING AND UNLOADING DEVICE v Filed Sept. 2, 1939 5 Sheets-Sheet 5 IN VEN TOR.

Q a 2? ,arromwm March 21, 1944. T R ROBINSON 2,344,923

LOADING AND UNLOADING DEVICE Filed Sept. 2, 1939 5 Sheets-Sheet 5 an mun IN V EN T 0R.

Tkoma: 1?. Robinson ATTORNEY.

Patented Mar. 21, 1944 UNITED STATES iATENT OFFICE LOADING AND UNLOADING DEVICE Thomas It. Robinson, Everett, Wash.

Application September 2, 1939, Serial No. 293,244

8 Claims.

This invention relates to a loading and unloading device particularly useful in the loading and unloading of a veneer hot plate press. It is to be expressly understood that in setting forth such particular utility of my invention I am not to be limited to any such specific field of utility and the invention is applicable to other fields where like problems exist in whole or in part.

The use of hot plate presses in the veneer or plywood art is becoming more and more common in view of the greater water resistance of the hot process glues over the cold process glues. Also less water may be used in hot process glues, and therefore the panels delivered from the hot presses contain less moisture content than those delivered from cold presses. This reduction of moisture content in the panels is desirable, as panels often check or crack when dried to reduce the moisture content. These, among other reasons, have been effective in increasing the use of hot plate presses in the veneer and plywood art.

Despite such increasing use of hot plate presses, no commercially satisfactory method has been heretofore devised to load and unload such hot plate presses. The hot plate presses comprise a plurality of heated platens movable away from each other to provide an open position. In this open position uncured panels may be inserted into the press between heated platens. Thereafter the platens are moved toward each other, providing heat and pressure on the panels to cure the same. Thereafter the platens are moved away from each other to provide the open posi-, tion in which cured panels are removed or unloaded from the press and uncured panels are inserted between platens or loaded into the press.

The uncured panels, which are loaded into the press or positioned between platens thereof, generally comprise a plurality of odd numbered plies, as 3, 5, 7, etc. In three ply panels there are two face members and the intermediate member, or the cross banding stock. The face members generally comprise a single sheet and the cross banding stock generally comprises a plurality of pieces in abutting edge to edge relation Glue material lies between adjacent faces of the face members and the cross banding stock. Due to the fact that the stock in the face members, as, well as in the cross banding stock, has generally been dried, it is common for the stock to be wrinkled and warped. These wrinkles and the uneven condition of the stock; are, of course, removed by the pressure in the ,hotplate press.

The cured P nel which s to be un oaded from the press, is often adhered to a platen. This adherence is caused by one or more of the following: (l) Overflowed glue which is squeezed or pressed out from the panels by the pressure between platens; (2) resins from the wood in the panels; and (3) suction or vacuum between a panel and a platen due to the pressure of the platens causing the panel to closely contact a platen surface.

Due to the fact that the platens are hot, and in the interest of most economical utilization of equipment and labor, it is obviously undesirable to load or unload hot plate presses by hand.

An attempt has been made to provide a mechanical loading and unloading device in which the incoming or uncured panel urges the cured panel out of the hot plate press. However, in view of the loose character of the incoming uncured panel, and the fact that the cured panels ar often adhered to the platens, such. mechanical loaders and unloaders are not satisfactory. For example, the incoming uncured panel may be disarranged by contact with a cured panel, even though the uncured panel is not adhered to a platen; (2 in the event of adherence of a cured panel to a platen, the disarrangement of the uncured panel may be such as to ruin such panel; (3) the looseness of the uncured panels is such that if they are employed to push out the cured panels, the uncured panels will not be symmetrically and centrally positioned in the press, thus unbalancing the press and causing damage thereto. Despite these objections and others, heretofore the only mechanical loaders and unloaders for veneer presses have employed means wherein the uncured panels urge the cured panels out of the press.

It is an object of this invention to provide independent panel contacting means, one of which urges the cured panel out of the press and the other of which urges the uncured panel into the press. It is a further object of the invention to provide an unloader means which will urge the cured panel out of the press at the same time an uncured panel is loaded into thepress, and which means may be retracted over but not contact the uncured panel and thus disarrange the same. It is a further object of the inventionto provide loader and unloader means with removable cross members so that the cross"member which unloads the cured panel from the press Will:be

discharged with the cured panel and the cross, member which urges the uncured panel into. the.

press will be used in, the nextcycle ofoperation to remove the cured panel, from the press.

It is a further object of the invention to provide a loader member with a plurality of spaced apart openings therein, which openings coincide with the openings between platens in the hot plate press when opened.

It is a further object of the invention to provide means to move a plurality of uncured panels from the loader member into the hot plate press during one stroke of operation and during the same stroke to-remove the cured panels from the hot plate press.

It is a further object of the invention to provide mechanism so that uncured panels may be inserted into the spaces or chambers of the loader I member while the device is operating;

It is a further object of the invention to provide a practical, economical and eflicient device which will fit in with present plant equipment and provide for rapid loading and unloading of hot plate presses. The rapid loading and unloading of hot plate presses not only economically utilizes the labor and machinery involved, but provides for a more economic utilization of the glue-this for the reason that there is less drying out of the glue by reason of rapid handling and therefore less glue may be used to obtain the same results.

The above mentioned general objects of my invention, together with others inherent in the same, are attained by the mechanisms illustrated in the following drawings, the same being preferred exemplary forms of embodiment of my invention, throughout which drawings like reference numerals indicate like parts:

Figure 1 is an end elevation of a loader and unloader device embodying this invention;

Fig. 2 is a side elevation of the device shown in Fig. 1, with parts broken away, and shown in operative position adjacent spaced apart platens of ahot plate press; I

Fig. 3 is a detached plan view of one set of loader and unloader bars of this invention and operative rack and pinion means therefor;

Fig. 4 is a detached perspective view, on a smaller scale, of one of the deck members over which the rack members of Fig. 3 are operated; Fig. 5 is a sectional view showing two spaced apart deck members of the loader and unloader device in operative position relative to two spaced apart platens of a hot plate press with the unloader bars in one operative position and with panels shown by dot and dash lines;

Fig. 6 is a view similar to Fig. 5 showing another operative position of said parts in Fig. 5;

Fig. '7 is a fragmentary plan view on a larger scale showing a portion of the rack, pinion and unloader bars of Fig. 3 (particularly the upper left hand corner thereof), in operative position relative to the deck member of Fig. 4;

Fig. 8 is a view partly in section and partly in elevation taken substantially on broken line B8 of Fig. 7;

Fig. 9 is a fragmentary view partly in section and partly in elevation taken substantially on broken line 9-9 of Fig. '7, showing a portion of one platen of a hot plate press and one deck member of a loader and unloader device and showing by dot and dash lines one position of the dog and unloader bar and by full lines a second position thereof into which the same will fall by gravity;

Fig. 10 is a fragmentary view similar to Fig.9

but showing theouterend of a press platen and the position the dog and unloader bar will assume on the return stroke;

Fig. 11 is a somewhat diagrammatic detached view showing a hydraulic and link belt means for operating the pinion means and in turn the racks operatively connected therewith (the control means being broken away as they are shown on larger scale in Fig. 12);

Fig. 12 is a somewhat diagrammatic view, on a larger scale, illustrating a control means for the hydraulic means of Fig. 11;

Fig. 13 is a somewhat diagrammatic view showing an alternative type of drive for the pinion and rack means where electric means replace the hydraulic means of Fig. 11; Fig. 14 is a view in elevation and similar to Fig. 5, but on a larger scale, showing a modified form of theinvention where an oscillating bar is used for loading as well as unloading and showing one operative position of the loading and unloading bar means and further showing an uncured panel as well as a cured panel by dot and dash lines;

Fig. 15 is a view similar to Fig. 14 showing the parts in a second operative position;

Fig. 16 is a view similar to Fig. 14 and showing a still further operative position of the parts;

I Fig. 17 is a view similar to Fig. 14 and showing a still further operative position of the parts;

Fig. 18 is a fragmentary view partly in section and partly in elevation of the in-feed end of the loadenillustrating the position of the dog and loading bar on the return stroke;

Fig. 19 is a View similar toFig. 18 but at the out-feedend of the loader, showing one position by dot and dash lines, a second position by full lines, and a third position by dot and dash lines illustrating the operation of the dog and loading bar on the return stroke;

Fig. 20 is a view similar to Fig. 19, showing one position by dot and dash lines and a second position :by full lines illustrating the operation of the dog and unloading bar on the return stroke;

, Fig. 21 is a plan view with parts in section and parts broken away of a still further modified form of the invention showing the hot plate press with a panel therein, the loader with a panel therein, and the loader and unloader bars and their operative mechanism;

7 Fig. 22 is a sectional view, on a larger scale, taken substantially on broken line 22-22 of Fig. 21 showing a guide means; i

' Fig. 23 is a plan view with parts broken away (if the parts shown in Fig. 21 and with the loader and unloader means shown in a second operative position;

Fig. 24 is a fragmentary plan view, on a larger scale, illustrating the bar catch mechanism;

Fig. 25 is a sectional view taken substantially on broken line 2525 of Fig. 23; v

Fig. 26 is a fragmentary sectional view similar to Figs. 18 to 20 of a modified form of the invention and illustrating friction means for operating the oscillating dogs and loader or unloader bar connected therewith;

Fig. 27 is a view similar to Fig. 26 except showing a second operative position of the dog and loader or unloader bar when the direction of travel is reversed;

Fig, 28 is a view similar to Fig. 14 with parts broken away showing a modified form of the inventionparticularly the deflector means; and

Fig. 29 is a plan view taken substantially on line 29--29 of Fig. 28. i. Referring particularly to Figs. 1 to 4, incl., the

loader and unloader device comprises a plurality of deck members 30 (see detached in Fig. 4), which are secured in spaced relation to provide a plurality of chambers 3| in registration with the chambers 32 between the platens 33 in the hot plate press, generally referred to as 34. To provide for adjustment so the loader and unloader device may be used with a plurality of kinds of hot plate presses, the deck members 38 are provided with lugs 35, which lugs are drilled to receive therethrough threaded members 36. Nuts 31 threadedly engage the members 36 and the same may be adjusted to provide the chambers 3| in registration with the chambers, 32 of the hot plate press 34 when the same is in open position.

. As the hotplate press 34 is no part of the invention, the same is only shown in part to illustrate the operative relation thereto of the loader and unloader device of this invention. It is understood, however, that the hot plate press 34 is provided with a plurality of platens 33 which have operative connections to a source of heat, which is generally steam. The platens are provided with means (not shown) to move the platens away from. each other to provide the open position, shown in Fig. 2, so that plywood panels may be inserted in the chambers 32 between the platens 33. Then the platens are moved relatively toward each other and the panels are cured by the application thereto of heat and pressure from the platens.

The members 35 are supported in position by frame members 33. Wheels 39 may be employed to provide desirable mobility to the loading and unloading device.

Pinions 29 and 48 are provided at opposite sides of the loader and unloader device. The pinions 29 and 45 may be provided with teeth throughout their length, as shown in Fig. 2, so the teeth of the racks 4| will always engage therewith despite adjustment of the nuts 31. The pinions 29 and 48 are driven in opposite directions a predetermined number of revolutions, stopped, and then driven in reverse directions a predetermined number of revolutions, by means hereinafter described.

The rack members 4|, which serve as carriage members, are supported and guided .by guides 42 on the deck members 38 (see Figs. 3, 4, 7 and 8) and reciprocate in the chambers 3| of the loader and chambers 32 of the press. The retracted position of the rack members is shown in Fig. and the advanced position in Fig. 6.

The loader bar 43 connects the racks 4|. In the form of the invention shown in Figs. 1 to 10, loader bar 43 is fixedly secured to the racks 4|. The unloader bar means referred to generally as 44 is mounted by the racks 4| and is provided with an oscillating movement.

Referring more particularly to Figs. 3, 7 and 8, the unloader bar means 44 comprises a transverse unloader bar 46 supported by pivot means 45 to the racks 4|. The unloader bar 46, on its forward or unloading stroke, is in the vertical position shown in Figs. 5, 6 and 9 and on its return stroke is in the horizontal position shown in Fig. 10. The dogs 47 insure that on its return stroke the unloader bar 45 will be in a horizontal position. On the return stroke the edges 48 of the dogs 41 ride on the surface of the platens 33 and insure such horizontal position on the return stroke. The deflector 43 is used to prevent irregular or warped portions of a panel 58 (as in Fig. 6) from being engaged by the unloader member 44 during the return stroke. The dogs 41 are positioned at the ends of the bars 46 and are therefore clear of the central portion where the panels 58 in the loader and panels 5| in the press are located.

As the pinions 29 and 48 are rotated in opposite directions, two racks 4| are projected into each of the chambers 3| and 32 from the position shown in Fig. 5 to the position shown in Fig. 6 and then, upon reversal, the racks are returned to the position in Fig. 5. This constitutes one cycle of operation. With the parts in the position shown in Fig. 5, an uncured panel 58 is inserted into the loader mechanism and ahead of the loader bar 43. The loader bar 43 extends the full width of a chamber 3|. As the racks 4| move forward, each loader bar 43 engages with an uncured panel 50 and moves the same out of the loader into a chamber 32 of the press as shown in Fig. 6. The extent of the forward stroke of the racks 4| and the loader bar 43 is adjustable (hereafter described in connection with Fig. 12), so panels of varying sizes may be loaded into a press and will be centrally positioned therein.

On the forward stroke of the racks 4|, the surfaces 48 of dogs 41 engage stops 46 and bar 46 serves to unload a panel from chamber 32 in the press by contact of the unloader bar 46 with a panel, as cured panel 5|. Because of the shape of the spring clips 52, the dogs 41 will depress the same on their forward stroke but the position of the dogs will not be changed. On the return stroke, the edges 48 contactwith spring clips 52 and oscillate the dogs 41 from the position shown in Fig. 6 to the position shown in Fig. 10, and thereafter the edges 48 will ride on the surfaces of the platens 33 and the unloader bars 46 will be maintained in a horizontal position where they will pass over and not disturb the uncured panels 58 which have been loaded into the chambers 32 of the hot plate press.

As the racks 4| near the end of their return stroke, the dogs 47 will pass off the ends of platens 33. The weight of the unloader bars 46 is such that by gravity they will move from the dot and dash line position to the full line position of Fig. 9. The dogs 41 will enter recesses 28 in the deck members 3|] to permit such turning of the unloader bars 46. The unloader bars 46 are then in the position shown in Fig. 5 and ready for their forward or unloading stroke.

In Figs. 1, 11 and 12 one type of drive means for reciprocating the racks 4| and parts connected therewith is shown. A fluid pressure cylinder 53 is provided with a slidin piston 54 therein. The piston rod 55 is connected with the piston 54 and is slidable through a packing member in an end wall 56 in the usual manner. The said drive means are supported by the frame members 38. The piston rod 55 is connected to driving chains 51 and 58 connected together as by buckle 59. The chain 51 is reeved around sprockets 68 and 6|. The sprocket 68 is fixedly mounted on shaft 62 which shaft also mounts pinion 29 (see Figs. 1 and 11). The sprocket 6| is an idle sprocket. Chain 58 is reeved around sprockets 63 and 64. Th sprocket 63 is fixedly mounted on shaft 65 which shaft also mounts pinion 48. As the piston rod 55 is moved in one direction, the sprocket 60, shaft 62 and pinion 29 will rotate in one direction and the sprocket 63, shaft 65 and pinion 49 will rotate in the opposite direction causing the racks 4| to be projected, and upon reverse movement of the rod 55 theracks 4| will be retracted; 1 .l

The control means for operating piston 54 may be the usual piston valve which is illustrated in Fig. 12. This mechanism comprises a chamber 66 and a slidable piston 61 therein arranged for movement into three positions. In one position (shown in Fig. 12) fluid under pressure (preferably hydraulic for smoothness of operation) from inlet conduit 58 connects with conduit 69 leading to one side of the piston 54 and the exhaust from cylinder 53 i through conduit 'lfland thence exhaust conduit H. In the second position, fluid from inlet conduit 68 connects with conduit 10 leading to the opposite side of the piston 54 and the exhaust from cylinder 53 is through conduit 69 and thence exhaust conduit 13. Rod 14 connectswith the piston 61 and is provided with the usual sliding packing connection. Spring 15 serves to urge the rod 14 and parts connected therewith into the position shown in Fig. '12. The third position is the stop position.

- Assuming the parts are in the position shown in Fig. 12, fluid under pressure will pass through inlet conduit 68, thence conduit 69 and against piston 54 urging the piston 54, rod 55 and parts connected therewith toward the right (as shown in Fig. 12). At the end of the desired travel of such piston 54, stop 16, carried by rod '55, will engage with stop H carried by rod 14, and move the .rod 14 and piston 81 to the, right (as shown in Fi 12). The stop .16 will engage fixecl'stop 18- at the time the piston closes both conduits 69 and 10 from inlet conduit 68, and the parts thus assume the said third or stop position which is the end of a cycle. At this stop position the racks 4| are retracted and in the positionshown in Fig. 5 of the drawings. I

To start another cycle of operation, the operator pulls lever 19 to the right. This moves piston 61 to the right and alsoLrod'l4. The spring '15 is compressed and stop 80 carried by rod I4 is moved past spring loaded catch 8|. Thereupon spring loaded catch 8| holds the rod 14 in this position. In such position, fluid under pressure flows from inlet conduit 68, through conduit 10 and against piston 54. At the same time, the exhaust from the other side of piston 54 connects'through conduit 69 to exhaust conduit 13. The piston 54 and rod 55 move to the left until adjustable stop 82 carried by rod 55 'engages with spring loaded catch 8|, releasingst'op 80 therefrom and permitting spring to return rod I4 to the position shown in Fig; 12;

When the rod 55 is moving to theleit in Fi'g. '12,

the racks 4| are making their forward strokeand the extent of such forward stroke may be 'adjusted by sliding adjustable stop 82 on the rod 55.

After the rod 14 has been returned to the position shown in Fig. 12, the piston 54 will moveto the right and the racks 4| connected therewith will be retracted until stop '16 engages stops 11 and 18 as previously describedi. 1

In Fig. 13, diagrammatically, is shown an alternative method of driving, the shafts 52 and. 65. These shafts :62 and 65 are connected to the pinions 29 and,40, and. the carriage means as racks 4| in thesamefimanner-as ,shovvnfiaudje scribed in the previous figures and in the interest of brevity are not further. describedwm; shown in thisfigure. The pinions 697 and '69 are connected with said shafts 62- and 65. Elec-. trio motor 83 is connected toa source of power (not shown) and drives speed reduction and-control means 84-which is in turn'.-connected::-to

shaft 85. Worms 86 and 81 are right and left hand threaded and mounted on shaft 85. The worms 86 and 81 mesh with pinions 60' and 63 respectively. By'means well known in the art, the control means 84 provides a cycle of operation so that the shaft 85 is turned .in one direction the desired number of revolutions and then reversed and turned in the other direction the desired number 'of revolutions.

In Figs. 14 to incl., 2. modified form of the invention is shown where the loader bars as well as the unloader bars are provided with an oscillating movement similar to the oscillating racks 4|.

movement of the unloader bar means 44 of Figs. 1 to 10, incl. The racks 4|, driving means therefor, deck members 30, chambers 3|, platens 33, and chambers 32 are the same as in the previous figures, and therefore similarly numbered. The primary purpose of providing oscillating loader as well as unloader means is to permit the loader and unloader device to be charged with uncured panels during movement of the racks 4| and means connected therewith.

The loader bar means, generally referred .to as 88, each comprise a transverse loader bar 89 pivotally secured at its respective ends to the Two dogs 90 (only one of which is shown), which are similar to the dogs 41 of the previous figures, are secured to the ends of loader bar 89. A deflector 9| similar to deflector 49 is provided so that panels 59 loaded into the loader during travelling movement of the loader bar 89 will not contact said loader bar 89. When the rack 4| is in its fully retracted position as shown in Fig. 14, the dogs 9|] rest on and are supported by spring loaded catches 92. The spring loaded catches 92 are depressible in recesses 93 in the deck members 30. V

The unloader bar means generally referred to as 94 are similar to the unloader bar means 44. The unloader bar means 94 each comprise a transverse unloader bar 95 pivotally secured between racks 4|. Two dogs 95 (only one oi which is shown) are secured to the ends of the bar 95. A deflector member 91 is similar to the deflector member 49 of the previous figures. The recess 98 in the deck member 30 is somewhat longer than the recess '38 so that spring loaded catches 99 may be provided ahead of the travel of the dogs 96 for purposes hereinafterdescribed. Assuming the parts are in the position shownv in Fig. 14 of the drawings, as the racks 4| move forward and in the direction of the arrow to the position shownin Fig. 15, the dogs 99 will engage with thespring loaded catches 92 and commence to rotate assuming the position shown in Fig. 15 of the drawings. As the movement of the racks 4| continues, the dogs. 99 will be rotated until the loader bars 89 assume a vertical position. The turning movement of the dogs 90is limited by stop means I06. After the dogs have turned until the loader bars 89 have assumed a vertical position, the loader bars will be in a position to engage with a panel 59 in a chamber 3|. The panel 50 may have been inserted in the chamber 3| during the previous stroke of the loader. bar means 88 as on its return stroke the loader'bar 89 is in a horizontal position. Also the panel 50 may have been loaded in a chamber 3| at'the end of a cycle when loader bar means 88 are at rest.

- At the same time the unloader bar 95 at the forward end of the racks 4| has assumed the positionshown in Fig. '14 of the. drawings where the dog '96 rests against stop 61' The vertical loader bar means 89.

position of the unloader bar 95 was assumed by gravity similarly to the vertical position of the unloader bar 46 of the previous figures. Unloader bar 95 will engage with a cured panel in the chamber 32 while the loader bar 99 engages with the uncured panel 50. Thus upon forward motion of th racks 4| and parts connected therewith, the cured panel 5| will be discharged and the uncured panel 59 will be loaded into the chamber 32 of the press. Such position is shown in Fig. 16 of the drawings where the racks 4| are at the end of their forward stroke and an uncured panel 59 has been inserted into a chamber 32 of the hot plate press. During the forward motion the dogs 99 and 96 respectively will depress spring loaded catches 99 and |9I respectively without effecting any change in the position of the dogs due to the angular direction of such spring loaded catches. Upon the return stroke the dogs 99 of the unloader bar means 94 will engage with spring clips I9I, which are similar to spring clips 52 of the previous figures. The dogs 96 and unloader bar 95 will be oscillated upon further return movement of the racks 4| (see Fig. 1'7), so that on the return stroke the unloader bars will assume a horizontal position similar to the horizontal position assumed by the unloader bar 46 of the previous figures. The dogs 99 of the loader bar means 98 will engage with spring clips 99 on the return stroke (see Fig. 19), depressing the spring clip 99 from the dotted line position shown in Fig. 19 to the full line position shown therein. The dogs 99 and loader bars 69 connected therewith will be oscillated so that on the return stroke, after the dogs 99 have engaged spring loaded catches 99, the unloader bars 89 will be returned in a horizontal position. In this way uncured panels 59 may be loaded into the chambers 3| during the operation of the The deflector means 9| will prevent a panel 59 from being urged direct- 1y into the unloader bar means 88. On the return stroke the surfaces I92 and I63 of the dogs 99 and 96 respectively will ride on the deck members 39 and the platens 33 respectively maintaining the loader bars 89 and 95 in a horizontal position. The unloader bar 89 is maintained in a horizontal position on the return stroke for purposes described in connection with the unloader bar 46 of the previous figures.

On the return stroke the dog 99 will ride over the spring loaded catch 92 in view of the angular position of such spring catch, and the loader bar 89 will be maintained horizontal at the end-ofthe stroke asshown in Fig. 14 of the drawings. On the return stroke as soon as the dog 96 is returned su'fiiciently so that it passes off a platen 33 by gravity the unloader bar 95 will rotate in the direction of the arrow as shown in Fig. 20

shown a still. further modified form of the in-.-

vention where detachable members are used for the loader and unloader bars. Pinions 29 and 49 the racks 4| lu s on the deck m mbers I g g .39, parts connected therewith, uncured panel 59,

andcured panel 5| are the same as such parts in hot plate press.

the previous figure's'and for that reason are given similar numbers.

Lug I94 are carried by the racks 4| and project inwardly sufliciently to support a loading bar I95 but not sufficiently to engage with an uncured panel 59 in the chamber 3| of the loader. On the forward ends of the racks 4| spring loaded pawls I96 project inwardly sufliciently to support an unloading bar I91 butdo not project inwardly sufficiently to engage with the cured panel 5|. On the forward stroke of the racks 4|, lugs I64 engage with the loading bar I65 which in turn engages an uncured panel 59. At the same time the spring loaded pawls I96 engage with an unloading bar I97 which in turn engages with a cured panel 5|. On th forward stroke the loading bar I65 and unloading bar I9I first slide along a deck 39 and then along a platen 33. The movement is continued until the cured panel 5| is discharged from the press and the parts assume the position shown in Fig. 23 of the drawings. The unloader bar I9! was discharged with the cured panel 5| and the loading bar I95 was moved into a chamber 32 in the hot plate press as shown in said Fig. 23. Upon the return stroke (see particularly Fig. 24) the racks 4| and spring loaded pawls I96 carried thereby will be returned until the spring loaded pawls I96 contact the bar I95. Upon contact the spring loaded pawls I95 move the loading bar I95 therewith until the loading bar I95 engages with steps I 93. Stops I93 project upwardly through the deck members 39 (see Fig. 25) and are spring loaded. The shape of these catches is such that on th forward stroke the bar I95 may pass thereover, but on the return stroke the bar I95 will be held thereby causing a release of the spring loaded pawls I96, and the spring loaded pawls will move back of the bar I95 and into the position shown in Fig. 21 of the drawings. At this time the loader bar I95 will now be in a position to function as an unloader bar and during the next cycle of operation will be the unloader bar I91. Thereupon a new loader bar I95 is manually inserted ahead of the lugs I94.

In view of the fact that in this form of the invention there are no cross ties between the racks 4!, preferably I provide depressible guides I99 shown in plan in Fig. 21 and in section in Fig, 22. At all times when the press is open the springs I I9 of the depressible guides I99 urge the guides I99 upwardly so they will guide the racks 4|, but when the press is closed and the platens 33 move toward each other the guides I99 will be depressed.

The mode of operation of the structure shown in Figs. 2.1 to 24 incl. may be briefly reviewed as follows: The unloader bar I 91 is in Position by reason of operations in the previous cycle. The cured panel 5| is in a chamber 32 in the hot plate press. An uncured panel 59 is inserted in place in a chamber 3| in the loader, and a loader bar I95 is placed on a deck member 39 ahead of the lugs I94. On forward movement of the racks 4| the unloader bar I91 slides along a deck member 96 and along a platen 33 engaging with a cured panel 5| and the panel 5| is discharged along with the unloading bar I91. At the same time the loader bar I 95 slides along a deck member 39 and a platen 33 carrying an uncured panel 59 into the As the loader bar I95 and panel 59 on their forward stroke engage with catches 199, the catches I 98 are depressed in View of their shape (see particularly Fig. 2.5). The leader bar I95 is moved into the hot plate press into the position shown in Fig. 23 of the drawings. Then upon retraction of theracks llv the loader bar-I55 remains in its position in thehOt plate press until the spring loaded pawls I05 engage with the end portions of the loading bar I05, Whereupon the spring loaded pawls I06 engage the loading bar I05, returning the loading bar out of the hot plate press, and until the loading bar enages with catches I08, whereupon the loadin bar I05 is held by the stops I08 and the sprin loaded pawls IilB are returned past the then stationary loading bar I05 and until the parts assume the position shown in Fig. 21 of the draw-1 ings.

Alternative forms of oscillating dogs and loading or unloading bars are shownvin Figs. 26 and i 27 of the drawings. These loading or unloading bars may be used in place of the oscillating loading or unloading bars shown in Figs. 1 to 2 0 of the drawings, In such figures the loading or unloading bar I H is mounted for oscillating movement on racks 4I similar tov the unloading bar 45, unloading bar 95 or loading bar 89. Dogs I I2 are connected upon the respective ends of the loading or unloading bar's vIII. Dogs H2 are provided With-friction surfaces as rubber H3 I which engage with a deck or platen H4. In. the

direction of travel shown in Fig.26 of the drawings, the rubber surface H3 will frictionally engage with a deck or platen H4 so that the loading or unloading bar. HI will assume a horizonstroke of the racks 4|. During the advancing position of the rack II the'dogs H2 will frictionally engage with a deckor platen I I4 and the loading or unloading bars lH will assume'th'e 'in the other direction of travel the said bar III is in a horizontal position.

An alternative form of deflector means is shown 5 in Figs. 28 and 29. In Figs. 14 to 1'7 two deflectors ill and 97 are shown. Unusually wrinkled and Warped stock may engage the deflector 91. To prevent such difliculty I provide the deflector ll! of said Figs. 28 and 29. In these figures, the

decks 3i), chambers 3|, platens 33, chambers 32, racks 4i, loader bar means 88, unloader bar means 94, are similar to the similar parts of Figs. 14 to 17 and are similarly numbered, The deilector H1 connects between racks 4i and is in the form of a sheet having portions I I8 and H9,

-' which portions are similar inshape and'function respectively to deflectors" 9| and 91. 'I he main body of the deflector II I provides a continuous surface between such portions H8 and H8 so tioned deck supporting meanspositionedinihori- 3, tal position, i. e., the position during the return that upturned ends of plies of an uncured panel 7 56 will not be caught by the deflector in passing thereover.

Obviously, changes may be made in the forms,

l. A loader and unloader for a plywood press having spaced apart horizontal platens providing press chambers therebetween, comprising vertically spaced apart horizontal .decks providing loading chambers in registration with and adjacent to said press'chambers: vertically posi-- zontal spaced'relation to said press; longitudinally reciprocable rack members positioned'at opposite sides of each loading chamber; unloader bar means extending between and moved by forward portions of the rack members; loader bar means extending between and moved by trailing portions of the rack members; and two vertically positioned driven pinion means positioned at opposite sides of the loading chambers, between said press and said vertically positioned deck supporting means, and connected respectivelywith said rack means at the respective sides of the loadin chambers and moving an unloader bar means and a loader bar means in a loader chamber and into and out of the registering press chamber to engage and intermittently advance material simultaneously through all the press chambers of'the plywood press. r

2.,Panel moving means operable in a chamber between two spaced apart deck members comprising a panel engaging bar extending crosswise of said chamber and angularly movable into a position substantially parallel to said deck members to clear a panel in said chamber and into another position substantially perpendicular to said deck members to engage a panel in said chamber; carriage means for moving said panel engaging bar; dog means connected with said panel engaging bar; deck contacting portions on said dog means angularly positioned relative to said panel engaging bar to hold said panel engaging bar parallel to said deck members when in deck contacting relation and when the carriage means are traveling in one direction; and stop means operatively positioned relative said panel engaging bar limiting movement of said panel engaging bar when in panel engaging position and when the carriage is traveling in the other direction. a

3. Panel moving means operable in a chamber between two spaced apart deck members com prising reciprocable carriage members positioned at the sides of the deck members i a panel engaging bar extending crosswise of said chamber and pivotally connected with said carriage members and movable into a position to clear a panel or into a position to engage a panelin said chamher; dog means connected with said panel engaging bar; and dog oscillating means positioned in the path of travel of said dog means engaging said dog means and moving said panel engaging bar from one operative position to another.

4. Panel moving means operable in a. chamber between two'spaced apart deck members comprising reciprooable carriage members'positioned at the sides of the deck members; a panel engaging bar extending crosswise of said chamber and pivotally connected with said carriage members and movable into a position to clear a panel or into a position to engage a panel in said c amber; dog means connected with said panel engaging bar; and resiliently supported dog oscillating means positioned in the path of travel of said dog means engaging said dog means and moving said panel engaging bar during one direction of travel from one operative position to another.

5. Panel moving means operable in a chamber between two spaced apart deck members comprising reciprocable carriage members positioned at the sides of the deck members; panel engaging means extending between and pivotally connected with said carriage members and movable into a position to clear a panel or into a position to engage a panel in said chamber; and means bar in a loading chamber and advance the same through a press chamber to a position of disirictionally engaging a deck member moving said panel engaging means into panel engaging position during one direction of travel and into a position clear of a panel during the other direction of travel.

6. Panel moving means operable in a chamber between two spaced apart deck members comprising reciprocable carriage members positioned at the sides of the deck members; panel engaging means extending between and pivotally connected with said carriage members and movable into a position above a, panel or into a position to engage a panel in said chamber; devices positioning said panel engaging means above a panel in said chamber when said carriage means is moving in one direction and to engage with a panel in said chamber when said carriage means is moving in the opposite direction; and deflector means carried by said carriage members above a panel in said chamber for preventing contact between said panel engaging member and irregular portions of a panel during the travel when the panel engaging means is above a panel.

'7. In a device for loading and unloading a press having spaced apart horizontal platens providing press chambers therebetween, spaced apart horizontal decks providing loading chambers in registration with and adjacent to said press chambers; longitudinally reciprocable carriage members positioned at opposite sides of each loading chamber; means for imparting forward and return movements to said carriage members; a plurality of separable panel moving bars adapted to extend across said chambers between said carriage members; bar engaging members carried by the rear end portions of said carriage members positioned to engage with and advance a pane moving bar through a loading chamber and into a, press chamber; yieldingly mounted bar engaging pawls carried by the forward end portions of said carriage members positioned to engage a.

charge and positioned to retract from said press chamber a panel moving bar that has been left in the intake end portion of a press chamber by said bar engaging members; and yieldably supported one way stop members positioned to arrest retractile movement of said panel moving bar before the return movement of said carriage members is completed, whereby said yieldingly mounted bar engaging pawls will be moved relative to said retracted bar into positions to engage with and advance said retracted bar through a press chamber on their next forward excursion. 8. A loader and unloader for a plywood press having spaced apart horizontal platens providing press chambers therebetween, comprising vertically spaced apart horizontal decks providing loading chambers in registration with and adjacent to said press chambers; vertically positioned deck supporting means positioned in horizontal spaced relation to said press; longitudinally reciprocable rack members positioned at opposite sides of each loading chamber; panel unioader means carried by forward portions of the rack members; panel loader means carried by the rack members and trailing said unloader means; and two vertically positioned driven pinion means positioned at opposite sides of the loading chambers, between said press and said vertically positioned deck supporting means, and

connected respectively with said rack means at the respective sides of the loading chambers and moving a panel unloader means and a panel loader means in each loader chamber and into and out of the registering press chamber to engage jand intermittently advance panels simultaneous- ,ly, through all the press chambers of the plywood press.

THOMAS R. ROBINSON. 

